Shitani Masahiro, Sasaki Shigeru, Akutsu Noriyuki, Takagi Hideyasu, Suzuki Hiromu, Nojima Masanori, Yamamoto Hiroyuki, Tokino Takashi, Hirata Koichi, Imai Kohzoh, Toyota Minoru, Shinomura Yasuhisa
First Department of Internal Medicine, Sapporo Medical University, S1, W16, Chuo-Ku, Sapporo, 060-8543, Japan.
Tumour Biol. 2012 Oct;33(5):1307-17. doi: 10.1007/s13277-012-0378-3. Epub 2012 Mar 29.
Aberrant DNA methylation has been implicated in the development of hepatocellular carcinoma (HCC). Our aim was to clarify its molecular mechanism and to identify useful biomarkers by screening for DNA methylation in HCC. Methylated CpG island amplification coupled with CpG island microarray (MCAM) analysis was carried out to screen for methylated genes in primary HCC specimens [hepatitis B virus (HBV)-positive, n = 4; hepatitis C virus (HCV)-positive, n = 5; HBV/HCV-negative, n = 7]. Bisulfite pyrosequencing was used to analyze the methylation of selected genes and long interspersed nuclear element (LINE)-1 in HCC tissue (n = 57) and noncancerous liver tissue (n = 50) from HCC patients and in HCC cell lines (n = 10). MCAM analysis identified 332, 342, and 259 genes that were methylated in HBV-positive, HCV-positive, and HBV/HCV-negative HCC tissues, respectively. Among these genes, methylation of KLHL35, PAX5, PENK, and SPDYA was significantly higher in HCC tissue than in noncancerous liver tissue, irrespective of the hepatitis virus status. LINE-1 hypomethylation was also prevalent in HCC and correlated positively with KLHL35 and SPDYA methylation. Receiver operating characteristic curve analysis revealed that methylation of the four genes and LINE-1 strongly discriminated between HCC tissue and noncancerous liver tissue. Our data suggest that aberrant hyper- and hypomethylation may contribute to a common pathogenesis mechanism in HCC. Hypermethylation of KLHL35, PAX, PENK, and SDPYA and hypomethylation of LINE-1 could be useful biomarkers for the detection of HCC.
异常的DNA甲基化与肝细胞癌（HCC）的发生发展有关。我们的目的是阐明其分子机制，并通过筛查HCC中的DNA甲基化来鉴定有用的生物标志物。采用甲基化CpG岛扩增结合CpG岛微阵列（MCAM）分析，对原发性HCC标本[乙型肝炎病毒（HBV）阳性，n = 4；丙型肝炎病毒（HCV）阳性，n = 5；HBV/HCV阴性，n = 7]中的甲基化基因进行筛查。采用亚硫酸氢盐焦磷酸测序法分析HCC患者的HCC组织（n = 57）、癌旁肝组织（n = 50）及HCC细胞系（n = 10）中所选基因及长散在核元件（LINE）-1的甲基化情况。MCAM分析分别在HBV阳性、HCV阳性和HBV/HCV阴性的HCC组织中鉴定出332、342和259个甲基化基因。在这些基因中，无论肝炎病毒状态如何，KLHL35、PAX5、PENK和SPDYA在HCC组织中的甲基化水平均显著高于癌旁肝组织。LINE-1低甲基化在HCC中也很普遍，且与KLHL35和SPDYA甲基化呈正相关。受试者工作特征曲线分析显示，这四个基因和LINE-1的甲基化能有效区分HCC组织和癌旁肝组织。我们的数据表明，异常的高甲基化和低甲基化可能共同参与了HCC的发病机制。KLHL35、PAX、PENK和SDPYA的高甲基化以及LINE-1的低甲基化可能是检测HCC的有用生物标志物。
